1. Field of the Invention
This invention relates to electroplating devices and more particularly to a mechanism for automatically attaching two-row pin strips, portions of which are to be plated, to a transfer carriage device which will move them through a succession of treatment areas to a point where they will automatically be removed from the transfer device.
2. Prior Art
This invention deals with an electroplating device which utilizes an electrical contacting transfer carriage for the removable carrying of items which are to be partially plated and wherein at least one treatment bath is positioned along the path followed by the transfer carriage, the treatment bath having end walls with slots therein for passage of the items attached to the transfer carriage.
Electroplating devices of this type have been disclosed, for example, in German Offenlegungffschrift No. 1,796,017. In such prior constructions, the items which are to be partially electroplated, for example, relay springs and the like, are passed through one or more elongated treatment baths, the items being suspended from electrically conductive transfer carriages. Only those areas of the items which are to be plated are actually dipped into the corresponding treatment liquids. In order for the items to be moved through the various treatment liquids at a uniform level, i.e. at a constant liquid penetration depth, the end walls of the treatment baths contain slots through which the items may pass. Treatment bath liquid levels are maintained by the use of circulation pumps which continuously pump back into the treatment baths the liquids which flow out through the end wall slots.
In prior constructions, the items which were to be electroplated were hung by hand from the transfer carriages. The transfer carriages were normally guided by means of appropriately designed roller members on a cathode rail fixed above the treatment baths. After passing through the individual treatment baths, the electroplated items were then removed from the carriages by hand. Thus fully automatical electroplating did not exist. Also, such prior devices were not suitable for the partial plating of two-row pin strips because of difficulties which arise in properly electrically conductively contacting the individual pins. For example, in the course of electroplating a pin strip, if just one pin in the strip was not properly electrically conductively contacted or grounded, then the entire pin strip would have to be scrapped or subjected to an expensive further treatment. This problem is extremely difficult to overcome even by using complex methods of individually grounding the pins because the conductive electric contact elements of the carriages are under the influence of the treatment liquids which are either strongly acidic or strongly basic and thus have a tendency to form an oxide skin on the conductive elements.
It would therefore be an advance in the art to provide a fully automatic electroplating device for the partial plating of two-row pin strips in which reliable electric contact of each of the pins is guaranteed.